A grisly accident like this is an unfortunate blow to public transportation. It cost at least 25 lives, according to news reports, and will scare some riders away from trains. It should be a wake-up call that the West Coast badly needs to upgrade its passenger rail infrastructure.

The crash in California is being blamed on human error: An engineer failed to stop for a red signal. But this kind of wreck could only have occurred because of California’s clunky, obsolete train system. On this route, two trains in opposite directions were routinely running on the same stretch of track. Why the singletracking? Because a tunnel, dating to the early 1900s, was never made wide enough for two trains. Obviously it is possible to operate a railroad safely with this limitation. But it means slower trains and a greater risk of catastrophe due to human error.

In a first-class rail system – like the electrified passenger trains in most of Europe, or the Northeast Corridor in the U.S. – trains in opposite directions can be segregated to separate tracks. These modern rail lines are also engineered to avoid grade crossings, passing above or below the cars on the street. Some also have technologies to stop a train even if an engineer fails to heed a signal. But in the rest of the U.S., passenger trains have been on life support since the 1950s. Most passenger lines (including the Metrolink commuter trains) have to share track with freight trains and to contend with grade crossings. California, despite its good environmental record, is still a state totally ruled by the automobile. It deserves a substantial investment in improving its trains.